
<template>
  <div>
    <el-popover 
      placement="bottom-start"
      popper-class="tree-popover"
      trigger="click"
      @hide="popoverHide"
      clearable>
      <el-tree 
        class="common-tree tree-line"
        clearable
        ref="tree"
        :data="data"
        :props="defaultProps"
        :show-checkbox="multiple"
        :node-key="nodeKey"
        :check-strictly="checkStrictly"
        default-expand-all
        :expand-on-click-node="false"
        :default-checked-keys="defaultCheckedKeys"
        :highlight-current="true"
        @node-click="handleNodeClick"
        @check-change="handleCheckChange">
      </el-tree>
      <el-select 
        slot="reference"
        ref="select"
        v-model="selectedData"
        :multiple="multiple"
        collapse-tags
        clearable
        @click.native="isShowSelect = !isShowSelect"
        class="tree-select">
        <el-option 
          v-for="item in options"
          :key="item.value"
          :label="item.label"
          :value="item.value">
        </el-option>
      </el-select>
    </el-popover>
  </div>
</template>
 
<script>
export default {
  name: "tree-select",
  // props: ["clear"],
  props: {
    el: {
      type: String,
      default () {
        return ''
      }
    },
    // 树结构数据
    data: {
      type: Array,
      default () {
        return [];
      }
    },
    // 是否可选根节点
    rootNodeChick: Boolean,
    // 是否清空数据
    clear: Number,
    defaultProps: {
      type: Object,
      default () {
        return {};
      }
    },
    // 配置是否可多选
    multiple: {
      type: Boolean,
      default () {
        return false;
      }
    },
    nodeKey: {
      type: String,
      default () {
        return "id";
      }
    },
    // 显示复选框情况下，是否严格遵循父子不互相关联
    checkStrictly: {
      type: Boolean,
      default () {
        return false;
      }
    },
    // 默认选中的节点key数组
    checkedKeys: {
      type: Array,
      default () {
        return [];
      }
    },
    width: {
      type: Number,
      default () {
        return 260;
      }
    },
    height: {
      type: Number,
      default () {
        return 360;
      }
    },
  },
  data () {
    return {
      defaultCheckedKeys: [],
      isShowSelect: false, // 是否显示树状选择器
      options: [],
      selectedData: [], // 选中的节点
      // style: "width:" + this.width + "px;" + "height:" + this.height + "px;",
      // selectStyle: "width:" + (this.width + 24) + "px;",
      checkedIds: [],
      checkedData: []
    };
  },
  watch: {
    isShowSelect (val) {
      // 隐藏select自带的下拉框
      this.$refs.select.blur();
    },
    clear: function (n, o) {
      //箭头函数  不然会发生this改变
      if (n != 0) {
        this.selectedData = [];
        this.$nextTick(() => {
          this.$refs.tree.setCheckedKeys([]);
        });
      }
    },
    selectedData (newData, oldData) {
      this.popoverHide();
      if ( newData == undefined || newData == null || newData == [] || newData.length == 0 ) {
        this.$nextTick(() => {
          this.$refs.tree.setCheckedKeys([]);
        })
      }   
    }
  },
  mounted () {
    if (this.checkedKeys.length > 0) {
      if (this.multiple) {
        this.defaultCheckedKeys = this.checkedKeys;
        this.selectedData = this.checkedKeys.map(item => {
          var node = this.$refs.tree.getNode(item);
          return node.label;
        });
      } else {
        var item = this.checkedKeys[0];
        this.$refs.tree.setCurrentKey(item);
        var node = this.$refs.tree.getNode(item);
        this.selectedData = node.label;
      }
    }
  },
  methods: {
    loadCheckedKeys () {
      if (this.checkedKeys.length > 0) {
        if (this.multiple) {
          this.defaultCheckedKeys = this.checkedKeys;
          this.selectedData = this.checkedKeys.map(item => {
            var node = this.$refs.tree.getNode(item);
            return node.label;
          });
        } else {
          var item = this.checkedKeys[0];
          this.$refs.tree.setCurrentKey(item);
          var node = this.$refs.tree.getNode(item);
          this.selectedData = node.label;
        }
      }
    },
    changeIsShowSelect () {
      this.isShowSelect = false;
    },
    popoverHide () {
      if (this.multiple) {
        this.checkedIds = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
        this.checkedData = this.$refs.tree.getCheckedNodes(); // 所有被选中的节点所组成的数组数据
      } else {
        this.checkedIds = this.$refs.tree.getCurrentKey();
        this.checkedData = this.$refs.tree.getCurrentNode();
      }
      this.$emit("popoverHide", this.checkedIds, this.checkedData, this.el);
    },
    // 节点被点击时的回调,返回被点击的节点数据
    handleNodeClick (data, node) {
      if (!this.multiple) {
        let tmpMap = {};
        tmpMap.value = node.key;
        tmpMap.label = node.label;
        this.options = [];
        this.options.push(tmpMap);
        this.selectedData = node.label;
        this.isShowSelect = !this.isShowSelect;
      }
    },
    // 节点选中状态发生变化时的回调
    handleCheckChange () {
      var checkedKeys = this.$refs.tree.getCheckedKeys(); // 所有被选中的节点的 key 所组成的数组数据
      this.options = [];
      if (!this.rootNodeChick)
        checkedKeys.forEach(item => {
          var node = this.$refs.tree.getNode(item); // 所有被选中的节点对应的node
          let tmpMap = {};
          if (node.childNodes.length == 0) {
            tmpMap.value = node.key;
            tmpMap.label = node.label;
            this.options.push(tmpMap);
          }
        });
      else
        this.options = checkedKeys.map(item => {
          var node = this.$refs.tree.getNode(item); // 所有被选中的节点对应的node
          let tmpMap = {};
          tmpMap.value = node.key;
          tmpMap.label = node.label;
          return tmpMap;
        });
      this.selectedData = this.options.map(item => {
        return item.label;
      });
    }
  }
  
};
</script>


<style lang="scss" scoped>
.common-tree {
  ::v-deep .el-tree-node {
    .el-tree-node__children {
      .el-tree-node {
        .el-tree-node__content {
          padding: 0 !important;
        }
      }
    }
  }
  
}
</style>
